Interface Extension
public interface Extension
This interface represents an X.509 extension.
Extensions provide a means of associating additional attributes with users or public keys and for managing a certification hierarchy. The extension format also allows communities to define private extensions to carry information unique to those communities.
Each extension contains an object identifier, a criticality setting indicating whether it is a critical or a non-critical extension, and an ASN.1 DER-encoded value. Its ASN.1 definition is:
Extension ::= SEQUENCE {
extnId OBJECT IDENTIFIER,
critical BOOLEAN DEFAULT FALSE,
extnValue OCTET STRING
-- contains a DER encoding of a value
-- of the type registered for use with
-- the extnId object identifier value
}
This interface is designed to provide access to a single extension,
unlike X509Extension which is more suitable
for accessing a set of extensions.
- Since:
- 1.7
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Method Summary
Modifier and TypeMethodDescriptionvoidencode(OutputStream out) Generates the extension's DER encoding and writes it to the output stream.getId()Gets the extensions's object identifier.byte[]getValue()Gets the extensions's DER-encoded value.booleanGets the extension's criticality setting.
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Method Details
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getId
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isCritical
boolean isCritical()Gets the extension's criticality setting.- Returns:
- true if this is a critical extension.
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getValue
byte[] getValue()Gets the extensions's DER-encoded value. Note, this is the bytes that are encoded as an OCTET STRING. It does not include the OCTET STRING tag and length.- Returns:
- a copy of the extension's value, or
nullif no extension value is present.
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encode
Generates the extension's DER encoding and writes it to the output stream.- Parameters:
out- the output stream- Throws:
IOException- on encoding or output error.NullPointerException- ifoutisnull.
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